Fittings for tubes and the like



May 29, 1934. E R ET AL 1,960,246

FITTINGS FOR TUBES AND THE LIKE Original Filed Aug. 15, 1928 2 Sheets-Sheet 1 IN ENTOR BY v, *M ATTORNEYS y 1934- H. J. KERR El AL FITTINGS FOR TUBES AND THE LIKE 2 Sheets-Sheet 2 Original Filed Aug. 15, 1928 VE TOR- ATTORNEY Patented May 29, 1934 9 1,960,246 FITTINGS FOR TUBES AND THE LIKE Howard J. Kerr, Westfield, N. J., and James E. Trainer, Barberton, Ohio, assignors to The Babcock & Wilcox Company, Bayonne, N, J., a corporation of New Jersey Application August 15,

Renewed Au 1928, Serial No. 299,654- gust 25, 1933 13 Claims. (Cl. 122-360) This invention relates to a fitting or return bend for connecting the ends of tubes or the like that may be parallel to each other. The return bend may also serve the purpose-of supporting the ends of the tubes to which they are connected in such a manner that expansion and contraction may take place.

The invention will be understood from'the description in connection with the accompanying drawings in which Fig. 1 is a vertical section through a boiler showing a superheater with which the tube fitting can be used; Fig. 2 is a side view partly in section showing the fitting on an enlarged scale; Fig. 3 is an end view taken along the line 3-3 of Fig. 2 and Fig. 4 is an edge view taken along the line 4--4 of Fig. 2.

In the drawings reference character lindicates a furnace of a boiler above which a water tube boiler is located. The boiler comprises banks 2, 8; and 4 of inclined tubes that are connected to downtake headers 5 at one end and uptake headers 6 at the other end. The lower ends of the lowermost downtake headers 5 are connected to a cross mud drum '7 and the headers themselves are connected by means of nipples 8 in the usual well known manner. Nipples 9 connect the upper ends of the uppermost downtake headers 5 to the water space of a steam and water drum 10. Circulating tubes 11 connect the upper portions of the uppermostuptake headers '6 to, the steam space of a steam and water drum 10. Baflles 12 and 13 are provided for directing the hot gases from the furnace 1 over the banks of tubes to the outlet for the gases between the nipples 9.

A pipe 14 connects the-steam space of the steam and water drum to the inlet header 15 for'the superheater that is located between the banks of tubes 2 and=3. The superheater header'15 is con nected by rows of tubes 16 with return bends to the outlet header of the superheater. The tubes 16 are bent at one end as shown at 1'7 and the other ends of these tubes are connected by means of the fittings or return bends 18 to be described more in detail below. A support 19 may be providedv for the tubes 16 intermediate the ends thereof, this support resting upon. the tubes of the bank 2 and the return bends 18 may be supported by the baffle 12. The uppermost row of tubes. 16 is connected to the superheater outlet header 20 which may be in turn connected to the steam main.

One ofthe fittings or return bends 18 is shown in detail in Figs. 2, 3 and 4. The fitting is made somewhat Y-shaped and comprises two substantially parallel branches 21 and. 22 that are connected to the ends of tubes. 16, preferably by means of the well known Thomson method of electric butt resistance welding, to join the ends of the tubes 16 to the ends of the branches 21 and 60 22. This can be done after'the fitting itself has been completed. The end 24 of the fitting 18 opposite the branches 21 and 22 is made round and is threaded internally from the end to some distance toward the branches, as indicated at 25. The end 24 thus forms an apertured stem. A tapered plug seat or ground valve seat 26 is provided beyond the threads 25. An externally threaded screw plug 2'1 fits the threaded portion of the end 24, this plug being provided with openings or holes 28 which form grooves inthe circular opening or recess 28' into which the end of a special tool may be inserted for removing the screw plug 27. The holes 28 are drilled entirely through the plug 27 in order to disclose any leakage that may take place between the valve 29 and its seat- 26. A tapered plug or valve 29 is provided with a ground surface to fit the valve seat 26. Threaded holes 30 extend a short distance into the valve 29 to enable screw bolts to be inserted for removing the valve and for grinding it to its seat in case of leakage. The inner end of the plug 2'! may be made rounded and the contacting iace 01 the valve 29 fiat, or vice versa, in order to-provide suitable contacting surfaces for the two, and also to provide an annular space with which the holes 28 communicate, thus enabling any leakage past the valve 29 to be detected.

The fitting or return bend 18 .may serve as a support for the tubes 16 by having the end portion 24 thereof extending into holes 31 in the baflle 12 or other support, each hole being preferably slightly larger than the end 24 to provide loose fits so that the same can move longitudinally to accommodate expansion and contraction.

Although the fitting has been described as being provided with an end portion with a hole therein and two branches that are substantially parallel at their ends, it is to be understood that the invention is not restricted to a fittingwith only two.

branches, as additional branches may-be provided and made substantially parallel in a similar manner without departing from the spirit or scope of the invention.

This invention is especially'useful in connection with superheaters and economizersor for a forced circulation water tube boiler, although it is N not limited to these particular uses.

The return bend fitting is formed so as. to give the steam or other fluid flowing through it an easy turn to minimize loss of pressure through turbulence in'passlng through the fitting. .The valve 29 and its seat 26 are preferably 'f conical shape tapered at an angle of 15, withreference to the center line or axis of the cone. The branches 21 and 22 diverge preferably at an angle of 30 from the center line of the fitting and are bent on an easy tially parallel an easy access to each other. This form provides 'for a tube cleaner that may be incurve to make the ends of the same substanserted through the opening in the end 24 for the purpose of cleaning the inside of the tubes 16.

We claim:

1. In a return bend having a plurality of branches adapted to be connected to tubes and having an opening giving access to said branches, a valve seated in said opening and so positioned that its face forms substantially a continuation of the inside walls of the fitting, and a plug threaded into the opening and engaging the valve to hold it on its seat.

2. In a return bend having a plurality of branches adapted to be connected to tubes and having an opening giving access to said branches, a valve seated in said opening, and'a plug threaded into the opening and engaging the valve to hold it on its seat, said plug and valve having contacting faces, one of which is curved.

3. In a return bend having a plurality of branches adapted to be connected to tubes and having an opening giving access to said branches, a valve seated in said opening, and a plug threaded into the opening and it on its seat, Said ings therethrough.

plug having one or more open- 4. In a return bend having a plurality of, branches adapted to be connected to tubes and having an opening giving access to said branches, a valve seated in said opening, a plug threaded into the opening and engaging the valve to hold it on its seat, said plug having one or more openings therethrough, and said valve having one or more threaded holes therein to receive screw bolts.

5. In a return bend having a plurality of branches adapted to be connected to tubes and having an opening giving access to said branches, a valve seated in said opening and: so positioned that its face forms substantially a continuation of the inside walls of the fitting, and means to hold said valve on its seat.

6. In -a return bend having a plurality of branches adapted -to be connected to tubes and having an opening giving access to said branches, 9. valveseated in said opening and so positioned that its face forms substantially a continuation of the inside walls of the fitting, removable means to hold said valve on its seat, and means for rotating said valve on said seat after removal of said holding means.

7. In combination with the fluid conducting tubes of fluid heat exchange apparatus, a branched fitting connecting a plurality of the tubes, an apertured stem projecting from the side of the fitting opposite the branches, said stem having a thickened wall portionformed to provide a valveseat adjacent the junction of the branches, a valve member having pressure tight direct engagement with the seat, the valve seat and valve being so positioned that the face of the valve member forms substantially a continuation of the inside walls of the fitting, a plug threaded into the stem to directly it into pressure tight engagement with its seat.

8. In combination with the fluid conducting tubes of fluid heat exchange apparatus, a return bend fitting having branches connecting a plurality of the tubes, an apertured tube supporting stem projecting from the side of the fitting opposite the branches, said stem having a wall portion with a contracting throat formed to provide a valve'seat adjacent the junction of the branches, a valve 1 member having pressure tight engagement withseat to close the passage through the stem,

1n the the valve seat and valve member being so posijtioned that theface of the valve forms substanengaging the valve to hold engage the valve and force tially a continuation of the branches of the fitting, a pressure applying structure having a part rotatable with'respect to the stem to force the valve member into its closed position.

9. In combination with the fluid conducting tubes of fluid heat exchange apparatus, a return bend fitting having branches connecting a plurality of the tubes, an apertured stem projecting from the side of the fitting opposite the branches, said stem having a tapering wall portion formed to provide a valve seat adjacent the junction of the branches, a valve member having pressure tight direct engagement with the seat, the valve seat and valve being so positioned that the face of the valve member forms substantially a continuation of the branches of the fitting, a hollow and perforated leak detector plug threaded into the stem to directly engage the valve and force it into pressure tight engagement with its seat.

10. In combination with the fluid conducting ,tubes of fluid heat exchange apparatus, a return bend fitting having branches connecting a plurality of the tubes, an apertured stem projecting from the side of the fitting opposite the branches, said stem having a tapered wall portion formed to provide a valve seat adjacent the junction of the branches, a valve member formed to have pressure tight engagement with the seat to close the passage through the stem, the valve seat and valve member being so positioned that the face of the valve forms substantially a continuation of the insidewalls of the fitting, a plug threaded into the stem to directly engage the valve and force it into pressure tight engagement with its seat.

, 11. In fluid heat exchange apparatus subjected to heating gases at high temperatures, tubes conducting a fluid through the gases, a branched fitand provided with a central projecting portion contacting the valve to cause the valve to contact with its seat over the entire circumference of the latter.

12. Fluid heat exchange apparatus comprising, in combination, a plurality of tubes conducting a fluid to be heated and subjected externally to heating gases at high temperatures, a tubular body joining the tubes at their ends and provided with an opening for the inspection and repair of tubes, portions of said body formed to constitute a valve seat, a valve member adapted to engage the seat and form a pressure tight closure, and a thrust member acting to force thevalve into pressure tight engagement with its seat and located wholly within the confines of said body.

13. In combination with the fluid conducting Lil) tubes of fluid heat exchange apparatus, a return bend having branches connecting a plurality of tubes, an apertured stem or neck extending from the sideof the fitting opposite the branches, said stem having a wall portion formed to provide a closure seat, a closure structure having pressure tight engagement with the seat to close the pas- 

